Nuprl Lemma : stable-union-decomp

[X,T:Type]. ∀[P:T ⟶ X ⟶ ℙ]. ∀[S:T ⟶ Type]. ∀[Q:i:T ⟶ S[i] ⟶ X ⟶ ℙ].
  stable-union(X;T;i,x.P[i;x]) ≡ stable-union(X;i:T × S[i];p,x.Q[fst(p);snd(p);x]) 
  supposing (∀x:X. ∀i:T. ∀s:S[i].  (Q[i;s;x]  (¬¬P[i;x]))) ∧ (∀x:X. ∀i:T.  (P[i;x]  (¬¬(∃s:S[i]. Q[i;s;x]))))


Proof




Definitions occuring in Statement :  stable-union: stable-union(X;T;i,x.P[i; x]) ext-eq: A ≡ B uimplies: supposing a uall: [x:A]. B[x] prop: so_apply: x[s1;s2;s3] so_apply: x[s1;s2] so_apply: x[s] pi1: fst(t) pi2: snd(t) all: x:A. B[x] exists: x:A. B[x] not: ¬A implies:  Q and: P ∧ Q function: x:A ⟶ B[x] product: x:A × B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a and: P ∧ Q ext-eq: A ≡ B subtype_rel: A ⊆B stable-union: stable-union(X;T;i,x.P[i; x]) prop: exists: x:A. B[x] so_apply: x[s1;s2] so_apply: x[s] so_apply: x[s1;s2;s3] so_lambda: λ2x.t[x] implies:  Q not: ¬A false: False so_lambda: λ2y.t[x; y] pi1: fst(t) pi2: snd(t) all: x:A. B[x]
Lemmas referenced :  double-negation-hyp-elim not_wf pi1_wf pi2_wf istype-void stable-union_wf subtype_rel_self istype-universe
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalHypSubstitution productElimination thin independent_pairFormation lambdaEquality_alt setElimination rename dependent_set_memberEquality_alt hypothesisEquality extract_by_obid isectElimination sqequalRule productEquality applyEquality universeIsType hypothesis independent_functionElimination lambdaFormation_alt productIsType because_Cache functionIsType dependent_functionElimination dependent_pairFormation_alt voidElimination independent_pairEquality axiomEquality instantiate universeEquality isect_memberEquality_alt isectIsTypeImplies inhabitedIsType dependent_pairEquality_alt

Latex:
\mforall{}[X,T:Type].  \mforall{}[P:T  {}\mrightarrow{}  X  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[S:T  {}\mrightarrow{}  Type].  \mforall{}[Q:i:T  {}\mrightarrow{}  S[i]  {}\mrightarrow{}  X  {}\mrightarrow{}  \mBbbP{}].
    stable-union(X;T;i,x.P[i;x])  \mequiv{}  stable-union(X;i:T  \mtimes{}  S[i];p,x.Q[fst(p);snd(p);x]) 
    supposing  (\mforall{}x:X.  \mforall{}i:T.  \mforall{}s:S[i].    (Q[i;s;x]  {}\mRightarrow{}  (\mneg{}\mneg{}P[i;x])))
    \mwedge{}  (\mforall{}x:X.  \mforall{}i:T.    (P[i;x]  {}\mRightarrow{}  (\mneg{}\mneg{}(\mexists{}s:S[i].  Q[i;s;x]))))



Date html generated: 2020_05_19-PM-09_36_17
Last ObjectModification: 2019_10_24-AM-10_17_20

Theory : int_1


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